IDHTGEC aka hero School
by Stuck-in-a-Fantasy04
Summary: This crossover also includes Trollhunters and GravityFalls. what happens when you take the multiverse's greatest heroes and send them off to interdimensional boarding school? Hiccup, Astrid, Peter, Shuri, Jim, Claire, Dipper, and Mabel had no idea what they were getting themselves into when they accepted Dr. Strange's invitation to I.D.H.T.G.E.C. but school isn't that bad... Right?
1. Chapter 1

**Well Nightwhip13 here and this is my first fanfic. So don't expect anything amazing. Btw this will be a crossover of as many fandoms as I wish. Namely HTTYD, Marvel, some Disney Princesses, Trollhunters, Gravity Falls, maybe RotG and Harry Potter. Of these I own none. The Interdimensional Hero Training Grounds and Education Center or I.D.H.T.G.E.C for short (I know, it's bad but I'll make it work. I'll probably turn it into some stupid joke) is my brainchild. I want to bring together a bunch of my favorite characters and throw them in a school together (I am aiming toward a modernized Hogwarts feel). For this fanfic I will be merging what I love about book Hiccup and movie Hiccup. For example, the dragon who accompanies him will be the night fury version of Toothless but certain things like dragonese(I might warp it a bit to fit my needs) and the kings lost things will be brought up and used.**

The bitter morning air bit through Hiccup's tunic. The blindfold about his eyes was itchy and uncomfortable. Toothless whined from a distance but Hiccup did not call out to reassure the dragon of his safety. A twig snapped off to his left and he tightened his grip on the sword he had dubbed Endeavor. A foul odor from the left, a swishing noise, a yell from the sidelines, and with a resounding clang he parried the blow with his sword. The momentum forced Hiccup off his good leg and he landed on the frozen ground with a thump. He pulled the blindfold off with an irritated huff. Toothless romped over to him and gave Hiccup a "are you okay?" look. Hiccup laughed as Toothless nuzzled him.

"That was a bit slow Haddock," Flashburn, Hiccup's instructor and headmaster of Flashburn's school of sword fighting, said, "Any slower and you would have a very nasty bruise on you shoulder right now and…"

"I know, if it was a real sword I would probably be lacking an arm and a leg," Hiccup said in a mechanical manner as he heaved himself to his feet and sheathed his sword.

"But you have done better than any student I have ever taught before and have the potential to be one of the most formidable swordsmen in all the known world," Flashburn stated confidently.

"Really? I was under the impression that I was doing horribly. You kick my butt every time we spar."

"Yes, but it's only your third month training with me and I actually have to try when sparing with you. Normally my students don't get to the level you are at till training with me for at least two years!"

"Well thanks." Toothless started to whimper and wave his prosthetic at Hiccup meaningfully, "Sorry bud I need to train too. We can fly later."

"Hiccup you have done enough for today. Go, have fun," Flashburn said. Without another word Hiccup leapt toward the jubilant Toothless and took to the sky.

* * *

"Karen, tell Happy I'll call him back," Spider-man said as he threw a punch at the Shocker, who had managed to slip away unnoticed on Homecoming night.

"He says it's urgent," Karen responded in her artificial voice which somehow seemed to hold so much emotion.

"Tell him I'll call him back after I mop the floor with this guy." He said as he flipped out of the way of an electrically charged gauntlet.

"I did but…"

"Peter!" Happy's voice buzzed sarcastically in his ear, "You know I wouldn't call unless it was important." Spiderman crawled up a building that was off to his left, leaving the shocker below to ponder how to smash a spider that was over twenty feet above you.

"I'm kinda in the middle of something," How did you get through? I told Karen to put you on hold."

"Tony gave me an override code for such an occasion as this."

"Of course he did," Peter huffed, irritated that even after the events of homecoming night Mr. Stark still didn't trust him completely.

"Speaking of Mr. Stark," Happy interjected, "he told me to get you to the new facility."

"Why?"

"That," said Happy, "is apparently none of my business. I'll pick you up in front of you apartment complex."

"Wait! Don't you have at least an idea of why?" Peter asked but his question was met with static.

"He hung up, Peter," Karen said.

'"Karen you're back!"

"It took me a little while to reboot, but yes, I am back," Karen said as Spider-man looked down to street level to see if the Shocker was still there. He hit the wall with a closed fist and felt the bricks crack with the force of his unnatural strength.

"He got away."

"Peter you should go home and get ready," Karen said, "You don't know when Happy will arrive."

"You're right Karen," he said.

Spider-man cast a web across the street and swung across the street as Peter Parker wondered how he could ever come to master this great power.

^ o ^

 **Is this okay? I'm sorry it's so short. I want to hear how I'm doing and see if you guys like it (I also have had this account for four months and really wanted to get something published). So please tell me if you liked it and give me any tips you might have. Next I will do an intro for Jim and the Pines Twin's point of view, then I will bring them all together. YAY!**

 **Really nervous, Nightwhip 13**


	2. Chapter 2

**Well, I'm back! Still really nervous. I don't know how this fanfic is going to go at all. So, the best thing to do is push through and hope that I can get through the intro and into the real writing. And I saw** **Infinity War** **opening weekend, well, I loved it, it was the saddest movie I have ever seen, and for this fanfic I have decided it will be set after Civil War because things happen in** **Infinity War** **that would ruin my plan for this fanfic. This also takes place before part 3 of Trollhunters.**

 **The Trollhunters:**

Beeep! Beep! Beeep! Jim lazily reached for his alarm clock and fumbled around in search of the snooze button. After finding the button, he settled in for another half-hour of sleep.

"Warhammer to, Trollhunter!" Jim nearly jumped out of his bed, "do you copy?" He lunged for the walkie-talkie that he had set on the far side of his desk.

"What is it Tobes? Goblins? Gumm gumms? Stalkling?"

"The algebra test isn't today is it?" Jim's best friend Tobias asked with genuine concern.

"Tobes, seriously? You want to know this at 6:30 in the morning! I was up late last night training and 'answering every call.' This trolllhunting business in going to give me insomnia… And no the test is tomorrow."

"Uhh, Jim? Its 7:30." Jim yelped, threw the covers off, and dropped the walkie -talkie. He quickly ran over to his dresser and threw the drawers open. After grabbing a few articles he ran to the bathroom to change, leaving the walkie-talkie on the floor. "Jim there is another thing, too… Jim? Okay I'll tell you later."

Five minutes later, Jim ran downstairs to get his book bag.

"I'm going to be so late," Jim muttered under his breath as he threw a waffle in the toaster and scrambled to shove all the books off the table and into his bag. The amulet of daylight fell out of his bag and, sensing his agitated state, began to form into armor around him. "No, no, no, not now," he said as he franticly tried to shake the armor off, to no avail.

"Jim, is everything okay?" Jim froze. If his mother came downstairs and found him in the armor…

"Yes, I'm all good. Just in a rush and burned my toaster waffle," he answered lamely.

"Since when do you burn any type of food?"

"Gotta go to school," he closed his bag, took a few calming breaths, grabbed the (perfectly cooked) toaster waffle, caught the amulet as it fell, and tucked it into the outer pocket of his bag, before saying goodbye to his mom and running out to get his bike.

"We're gonna be late, Jimbo!" Jim's best friend Tobias yelled from outside as he strapped a helmet around his chubby face.

"I know! I know!" Jim said as he hastily put on his own helmet and mounted his bike. Toby looked at Jim's bag in a dejected way.

"No lunch today?"

"Nope we're going to have to risk cafeteria food today."

"I hope it's not chicken surprise," Toby said in a scared voice. Jim started pedaling his bike and Toby followed suit. "Oh and I saw this weird orange, sparky, swirly thing appear behind your house."

"Great, it's probably some weird troll magic phenomenon that will cost me another night of sleep." Jim and Toby zipped along their normal route to school. When he reached the canal and his bike flew up into the air, for a fraction of a second he thought he saw a man standing in front of the wall which opened the portal to Trollmarket when he landed he turned around only to find that the man was gone. Toby came down the slope and fell flat on his face.

After recovering he asked, "What is it Jimbo?"

"I thought I saw… there was a man… he… he was wearing some weird red cape… nevermind." Jim shook his head.

"Uhh, Jim, are you sure you had enough sleep last night?" Jim shook his head again and mounted his bike. He rode off without another word. "Hey wait up, Jimbo!"

After School that day:

"I am swamped Tobes! Social studies, algebra, and Trollhunting… looks like I'm not gonna be making up any hours of sleep tonight. Tobes are you even listening to me?" Tobey had caught sight of Darcy from across the locker hall and attempted to throw his locker shut with a certain amount of swagger, but it failed miserably and he scrambled to pick up his books and retain his dignity.

"Are you trying to impress Darcy again, T.P.?" Claire asked as she walked away from her snickering friends. Tobey gave her a look that clearly said "shut up, not all people are great at flirting."

"Claire!" Jim cried jubilantly, "are you coming with us to the canal today?"

"Of course I am." Claire narrowed her eyes. "Are you sure you should be? You look extremely sleep deprived."

"Tobey and I think we saw some weird stuff around my house this morning. We need to check it out."

Tobey chimed in, "If it's a weird thing, it's a troll thing!"

"Fine but we should get home by at least ten tonight," Claire agreed reluctantly. Jim swung his backpack over his shoulder.

"We're all in agreement then. We will be Trollhunting today but we will attempt to be back by ten." They each mounted their bikes and headed to the canal. The southern California heat made the short bike ride feel like it dragged on for ages. When they finally entered Trollmarket everything was in chaos.

"HUUUUMAN! HUMAN IN TROLLMARKET," Bagdwella was shrieking, "TROLLHUNTER, DO SOMETHING!"

Jim, Claire, and Tobey stared slack-jawed at the commotion. Blinky ran up to the trio panting.

"Master Jim, thank goodness you're here! There's a strange magician here who wishes to speak with you."

"What does he want?" Jim asked as he and the others began to follow Blinky toward the Hero's forge.

"He has not told me the reason for his being here nor the reason for his odd attire."

When they reached the Hero's forge they saw another human figure standing in the middle of the circular room.

"Hey I saw you earlier!" Jim exclaimed upon seeing the man's red cloak.

"Hmm. I was trying to be inconspicuous. Clearly that didn't work," The man said, "You must be Jim."

"I am. These are my friends Claire and Toby," Jim said, "and who might you be?"

"Doctor Strange. And I have a proposition to make." Blinky then interjected.

"Master Jim would not listen to any proposition."

"You misunderstand my intentions. I am offering your young hero an opportunity for a higher education."

"Where?" Jim asked.

"In another dimension, far off in the multiverse. And, yes, Claire and Toby can come, too. It's called the Interdimensional Hero Training Grounds and Education Center or I.H.T.G.E.C."

"Some name."

 **The Mystery Twins:**

Dipperleaned his head against the bus's window and stared at the redwoods and pines that were flying by. He then glanced down at his shoulder where Mabel, fast asleep, was resting her head. She was drooling all over his shirt and part of Dipper wanted to shove her off, but he let her sleep. He probably would have done the same to her if he was that tired, anyway. Besides with Mabel's unpredictable mood swings and tendency to get cranky when she was tired, it was best to just let her be. Dipper reached into his backpack and pulled out the notes he and Mabel had received from their friends the last two summers when they had to leave Gravity Falls. The first was signed by most of their friends and was from the first, very eventful, summer at Gravity Falls. The second was very much the same, but as he and Mabel had made more friends in the small Oregon town the lack of unsigned space on the paper had grown. Mabel let out a little grunt and her head slipped a bit. Dipper looked up from the paper and resumed staring out the window.

I had been only the previous Thursday when Great Uncle Ford had called and explained to Dipper and Mabel's parents that a "very much coveted" education opportunity had opened up in Gravity Falls. Plans were then made for the weekend trip and the twins were sent off on a bus to the very town they had left only two months prior. Dipper had no idea what this education opportunity was, but whatever Ford and Stan had told his parents to let him and Mabel come had worked. Mabel had been ecstatic when then they had been told they were going to be returning to Gravity Falls. She had run around the house screaming and started packing her favorite sweaters. Dipper, if he was to be completely honest, was as excited as Mabel was, if not more. They had only been gone from Gravity Falls for about two months, but considering none of their friends had an email address or a phone, other than Wendy and Pacifica, it felt like an eternity since they had last seen most of their friends. The bus then hit a pothole jerking Dipper back to reality. He then saw something that made him smile. A Gnome was standing on a rock waving for his compatriots to circle near. The gnomes then caught sight of the bus and the twins in it and their jaws dropped. Dipper chuckled. Dipper guessed that it would be about 10 minutes until their arrival in Gravity Falls and that would be just enough time to wake Mabel up gently.

"Mabel. Wakey wakey," Dipper said gently as he gently shook her.

"mmmnoo, mabbl not here…"

"Mabel, we've almost reached Gravity Falls. All our friends will be there. Soos, Wendy, Candy, Grenda, Pacifica and Gruncle Stan and Great Uncle Ford. They might even bring Waddles." Upon hearing the word "waddles" Mabel cracked her eyes open.

"Do you really think Gruncle Stan would let them bring waddles to the station?"

Mabel asked.

"Stan would do anything for you Mabel."

"Mmmm… and Wendy will be there."

"Now you're awake. And I got over my crush on Wendy over a year ago." Mabel sat up, wiped the drool off her chin, and smoothed out her sweater.

"I know, but that doesn't mean I'll ever stop bugging you about it," Mabel said with a smirk. "We are siblings after all." Dipper rolled his eyes and started to pack up his stuff. Three pencils, two pens, the two notes from their Gravity Falls friends, a new journal, a sketchbook, and a deck of cards where all picked up and shoved into Dippers backpack in no particular order. Mabel smiled and took the sweater she had made for Waddles out of her backpack.

"Waddles!" Mabel cried as she stepped of the bus. Dipper smiled as he saw the assortment of people who had come to welcome them back to Gravity Falls. Gruncle Stan, Great Uncle Ford, Soos, Melody, Wendy, Candy, Grenda, and even Pacifica, who was glancing around warily because she probably didn't have permission to be there, had come to greet them. Mabel bent over to give her enthusiastic pig a hug and a sweater. Everyone else took that as their cue to begin the hug-fest. A Gravity Falls Pines family hug-fest didn't normally last long because Mabel did all the hugging, but this wasn't only the Pines family everyone gave the twins hugs and "nice to see you's and "welcome back"s. When Melody pulled away from hugging Mabel, Mabel let out a high-pitched shriek. At first Dipper thought it was because Melody's hand was caught on Mabel's sweater, but after looking at her hand more closely Dipper found the reason for Mabel's shrieking. Mabel screamed joyously as she helped Melody get her diamond ring untangled from her sweater.

"You're getting married?" Dipper said. Soos wrapped his arm around Melody and smiled.

"We were going to surprise you dudes later but Melody forgot to take the ring off." Dipper and Mabel stared at the couple. "Well… surprise, dudes."

"When? Was it romantic? When is the wedding? Can I help plan the wedding?" were some of the questions Mabel was flinging at Soos during the drive back to the Mystery Shack. Dipper, on the other hand, was trying to put the pieces together and figure out what the two Gruncles had called them up for. He eventually gave up. It was hard to think over Mabel's constant babble and he wanted to show his support for Soos and Melody's engagement. They explained some of the details of their wedding plans and asked for the Twin's input on cake flavors, types of flowers, and whether or not to invite the multibear.

"I could knit tablecloths for you!" Mabel suggested.

"Look we're here," Dipper cried. Mabel gave him a look.

Once they got out of the car Dipper ran into the Mystery Shack and looked around. There were too many people to ride in the one car so the two gruncles, Wendy, and Pacifica had let Gruncle Stan drive them there and had gotten to the shack before the passengers of Soos's car. The Shack hadn't changed much in the past two months.

"Hey, Dipper," Wendy called, "got my hat?" He exchange of their hats had become tradition for the two. Whenever the twins were in Gravity Falls Dipper would get his ball cap from Wendy and Wendy would wear her lumberjack hat. Whenever the twins had to leave Gravity Falls Wendy and Dipper would exchange hats again, the hats served as a something to remember Gravity Falls by.

"Of course I do," Dipper said as he reached into his backpack and pulled the worn hat out. He handed it to Wendy and in return Wendy ruffled his hair and walked behind the counter. Dipper followed her and she took his hat out from behind the desk and playfully tugged it onto his head. In the last couple years, as his crush on Wendy had subsided, he had come to think of her as an older sister. Mabel still bugged him about having a crush on Wendy though. He smiled at her and adjusted the hat.

"Hey," Dipper said, catching their reflection in a mirror, "I'm only a few inches shorter than you."

"Don't think you'll ever pass me up though," she said and went over to give Mabel her hug.

Dipper then spotted Pacifica standing behind a rack of T-shirts looking warily out the window. Walked over to her and attempted to start a conversation.

"So, how has school been so far?" Pacifica jumped and spun around.

"Actually, my parents hired a tutor to homeschool me. I'm actually supposed to be at a lesson right now." She glanced out the window again.

"What kind of lesson?"

"How to Maintain the High Society Stereotype," Pacifica sighed. Over the past few years Pacifica's ego had deflated a bit and she had become one of the twin's closest friends. Dipper looked at her sympathetically. "Rule one is 'you are who you hang out with' so if that's you and Mabel I'm already who I want to be." She looked up and smiled. Dipper enfolded her in a hug and Mabel jumped out from behind a merchandise rack to join in the hug.

"Mabel, what the heck!" Dipper cried in shock as he and Pacifica nearly fell over. They regained their balance and Pacifica laughed.

Later that evening the Pines family was sitting down for dinner in the Mystery Shack. Soos and Melody were at Soos's abulita's for the night because she hadn't been in great health lately and Wendy and Pacifica had gone home earlier that night.

"So, are you going to tell us why we're here?" Dipper asked after a long silence.

"Right. That," Ford said distractedly, "well I found a letter from an old friend saying that he would like to meet you two. It also spoke of a school that was being set up for young heroes. You two have been extended an invitation!"

"That's great!" Mabel said as she jumped up and almost knocked over her plate of brown meat. Dipper was confused by his great uncle's not-so-happy tone of voice as he had told them about the school.

"Why didn't you tell us earlier? Transferring schools isn't that big of a deal."

"It's in another dimension, dimension 563UO13, and I figured that after our prior experience with beings from other dimensions you might not be so eager to…"

"Are you kidding?" Mabel almost shouted. "We can make new friends and swap stories and… Ooh! Did you say for young heroes? People like us from other dimensions? Have they gone on adventures as crazy as ours?"

"Slow down, Mabel, you're going to hyperventilate. But seriously, Uncle Ford, where did you meet this guy?"

"I actually met him in the weirdness dimension," Ford responded. Gruncle Stan nearly choked on his water. After recovering the coughing fit that ensued, he looked at his brother with skepticism.

"Ford, why are we trusting this guy? He could be in league with Bill!"

"Gruncle Stan is right."

"Thank you, Dipper."

"He isn't from the weirdness dimension. The Doctor was pulled into Bill's domain by an accidental rip in the fabric of space and time." Dipper, Mabel, and Stan stared.

"I want to say I understand, but I really don't," Dipper said.

"I'll try to explain but it might be better if you just ask The Doctor when he gets here," Ford repied.

"Doctor who?"

"I don't know and that's beside the point, Dipper. Anyway, he travels through space and time in a small blue box accompanied by a girl named Rose. When I met him he was trying to fix his TARDIS so he could get home."

"What's a TARDIS?"

"Mabel! I would explain if you two would be quiet." Stan laughed quietly at his brother's outburst. "TARDIS stands for time and relative dimensions in space and it is the machine he uses to travel through space and time. We ran into some complications but nothing our little team couldn't handle. Anyway, once he got it fixed he tried to get us all out of that horrid dimension, but I stayed behind so they could escape. We were being chased by flying eyeballs you see. Huh, I was only 34 then. He should be arriving at the shack any minute now."

"How old are you guys anyway?" Mabel asked.

"24," Stan said and they all laughed.

After dinner the Pines were busying themselves with small things around the shack. Mabel was tailoring Waddles's sweater, Stan was calculating his cut from the Mystery Shack profits, Ford was tinkering with one of his inventions, and Dipper was washing the dinner plates as Stan had told him to. He was staring out the window at the infinite expanse of forest when suddenly a whooshing sound came from the basement.

"Kids!" Ford yelled, "He's here!" Together the Pines family went behind the vending machine and into the basement. When they were down the staircase they heard shouting.

"Amy! Which dimension is this?"

"The TARDIS says we're in some place called Gravity Falls, Oregon."

"Thank you, Pond."

Then to Ford and the rest of the family's surprise a man with long-ish brown hair, a bowtie, suspenders, and a fez stepped out of a blue police box. Dipper assumed this was the TARDIS and that the man was the Doctor. Ford, on the other hand, looked rather confused.

"Excuse me where is the Doctor?" The oddly dressed man took a double take. He ran a hand through his hair and looked Ford over closely. Sudden realization lit up the man's eyes.

"Ahh, Stanford! From that time when I got stuck in the dimension with the flying eyeball things! Love the flying eyeballs!"

"Where is the Doctor?" Ford appeared to be losing patience.

"Right, new face. I'm the Doctor. You see we Time Lords, when we're about to die, do this thing where we change and… err… don't die."

"How do I know it's you?"

"You confessed that your greatest regret was that you didn't stick up for your brother when your parents kicked him out." Upon seeing Ford's positive reaction and the tears that were beginning to form in Stan's eyes, he began to address the twins, "You must be Mable and Dipper."

"I have so many questions! How does it travel through time? Who else in in there? If you can go across dimensions why didn't you come back for Ford?" Dipper asked in a rapid fire manner.

"Ooh! A bowtie! Look Gruncle Stan you aren't the only crazy who likes fezzes! I know unicorns are real, but are pegasuses?" Mabel said at the same time as Dipper threw his questions at the Doctor.

"Pegasi, Mabel. The plural of Pegasus is pegasi." Mabel stuck her tongue out at Dipper and Dipper gave her a 'wow real mature' look.

"See, Amelia, River, bowties are cool. Mabel thinks so," The Doctor yelled at the TARDIS. Sounds of disagreement came from the TARDIS's cracked door. "I'll answer your questions on the way. You have stuff packed don't you? We have several princesses, two Vikings, three dragons, an ice elemental, a few ponies, and yes some of them used to be pegasi, who are still gawking at their hands, and various others waiting to get to I.D.T.G.E.C."

"Dragons?"

"Princesses and pegasi?"

"Wait. How do you fit all those people into there?"

"Come look," the Doctor said. He snapped his fingers and the TARDIS doors flew open.

"It's bigger on the inside," Dipper stated simply as he and Mabel stared slack-jawed at the amazing machine.

 **Well I'm definitely more proud of this chapter than I am of the last one and am looking forward to continuing this story.**

 **-Nightwhip13**


End file.
